This invention relates generally to a process for selective adsorption and recovery of lithium from natural and synthetic brines, and more particular to a process for recovering lithium from a natural or synthetic brine solution by passing the brine solution through a lithium selective adsorbent in a continuous countercurrent adsorption and desorption circuit.

This invention relates generally to a process for selective adsorption and recovery of lithium from natural and synthetic brines, and more particular to a process for recovering lithium from a natural or synthetic brine solution by passing the brine solution through a lithium selective adsorbent in a continuous countercurrent adsorption and desorption circuit.

A method of producing lithium phosphate from a lithium source includes the step of (a) concentrating the lithium to produce a lithium concentrate, with an ion exchange sorbent, and (b) reacting the lithium concentrate with phosphate anions to produce lithium phosphate. The lithium phosphate may then be converted to lithium hydroxide or lithium 5 carbonate by reaction with calcium hydroxide or by electrolysis.

A method of producing lithium phosphate from a lithium source includes the step of (a) concentrating the lithium to produce a lithium concentrate, with an ion exchange sorbent, and (b) reacting the lithium concentrate with phosphate anions to produce lithium phosphate. The lithium phosphate may then be converted to lithium hydroxide or lithium 5 carbonate by reaction with calcium hydroxide or by electrolysis.

The present disclosure relates to a method for extracting lithium from a lithium-containing material. For example, the method can comprise leaching a roasted lithium-containing material under conditions suitable to obtain an aqueous composition comprising a lithium compound such as lithium sulfate and/or lithium bisulfate. The aqueous composition comprising lithium sulfate and/or lithium bisulfate can optionally be used, for example, in a method for preparing lithium hydroxide comprising an electromembrane process. The roasted lithium-containing material can be prepared, for example by a method which uses an aqueous composition comprising optionally lithium sulfate and/or lithium bisulfate which can be obtained from a method for preparing lithium hydroxide comprising an electromembrane process such as a two-compartment monopolar or bipolar electrolysis process.

The present disclosure relates to a method for extracting lithium from a lithium-containing material. For example, the method can comprise leaching a roasted lithium-containing material under conditions suitable to obtain an aqueous composition comprising a lithium compound such as lithium sulfate and/or lithium bisulfate. The aqueous composition comprising lithium sulfate and/or lithium bisulfate can optionally be used, for example, in a method for preparing lithium hydroxide comprising an electromembrane process. The roasted lithium-containing material can be prepared, for example by a method which uses an aqueous composition comprising optionally lithium sulfate and/or lithium bisulfate which can be obtained from a method for preparing lithium hydroxide comprising an electromembrane process such as a two-compartment monopolar or bipolar electrolysis process.

A method for transforming a crystal form of an electrolyte containing lithium for aluminum electrolysis includes the following steps: S1, pulverizing the electrolyte containing lithium; S2, uniformly mixing an additive with the electrolyte powder to obtain a mixture, wherein the additive is one or more selected from the group consisting of an oxide of an alkali metal other than lithium, an oxo acid salt of an alkali metal other than lithium, and a halide of an alkali metal other than lithium; a molar ratio of a sum of alkali metal fluoride contained in the electrolyte, alkali metal fluoride directly added from the additive, and alkali metal fluoride to which the additive is converted under the high-temperature calcination condition in the mixture to aluminum fluoride is greater than 3; S3, calcining the mixture at a high temperature.

A method for transforming a crystal form of an electrolyte containing lithium for aluminum electrolysis includes the following steps: S1, pulverizing the electrolyte containing lithium; S2, uniformly mixing an additive with the electrolyte powder to obtain a mixture, wherein the additive is one or more selected from the group consisting of an oxide of an alkali metal other than lithium, an oxo acid salt of an alkali metal other than lithium, and a halide of an alkali metal other than lithium; a molar ratio of a sum of alkali metal fluoride contained in the electrolyte, alkali metal fluoride directly added from the additive, and alkali metal fluoride to which the additive is converted under the high-temperature calcination condition in the mixture to aluminum fluoride is greater than 3; S3, calcining the mixture at a high temperature.

The production method is a method for producing a positive electrode active material for a lithium ion secondary battery which contains at least nickel and lithium, the method including: a firing process in which a mixture of a nickel compound powder and a lithium compound powder is fired; and a water washing process in which a lithium-nickel composite oxide powder obtained in the firing process is washed with water, wherein the firing process is performed under conditions such that a value obtained by dividing a ratio of an amount-of-substance of lithium to a total amount-of-substance of transition metals other than lithium in the lithium-nickel composite oxide powder after the washing with water by a ratio of an amount-of-substance of lithium to a total amount-of-substance of transition metals other than lithium in the lithium-nickel composite oxide powder before the washing with water exceeds 0.95.

The production method is a method for producing a positive electrode active material for a lithium ion secondary battery which contains at least nickel and lithium, the method including: a firing process in which a mixture of a nickel compound powder and a lithium compound powder is fired; and a water washing process in which a lithium-nickel composite oxide powder obtained in the firing process is washed with water, wherein the firing process is performed under conditions such that a value obtained by dividing a ratio of an amount-of-substance of lithium to a total amount-of-substance of transition metals other than lithium in the lithium-nickel composite oxide powder after the washing with water by a ratio of an amount-of-substance of lithium to a total amount-of-substance of transition metals other than lithium in the lithium-nickel composite oxide powder before the washing with water exceeds 0.95.